Calculator.



L. B. THOMAS.

CALCULATOR.- APPLIOATION FILED APR. 11. 1910.

Patented May 23, 1911.

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Patented May23, 1911.

L. B, THOMAS.

'GALGULATOR. APPLIOATION FILED APR.11, 1910.

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CALCULATOR.

Patented May 23, 1911 3 SHEETS-SHEET 3.

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www'zooao LIITHER B. THOMAS, OF SHREVEPORT, LOUISIANA.

CALCULATOR.

Specification of Letters Patent.

Patented May 23, 1911.

Application filed April 11, 1910. Serial No. 554,773.

T 0 all whom it may concern: I

Be it known that I, LUTHER B. THOMAS, a citizen of the United States,residing at Shreveport, in the county of Caddo and State of Louisiana,have invented certain new and useful Improvements in Calculators; and Ido declare the following to be a full, clear, and exact. description ofthe invention, such as will enable others skilled in the art to which itappertains to make and use the same. 4 v

This invention relates to improvements in calculators.

The object of the invention is to provide a calculator constructed andarranged to,

afford an absolutely accurate and almost instantaneous means forascertaining the value of various-quantities of merchandise at differentprices per pound, yard, bushel, and the like. I

With this and other objects in view, the

invention consists of certain novel features of construction,combination and arrangement of parts as will be more fully described andparticularly pointed out in the appended claims.

In the accompanying drawings: Figure 1 is a plan view of a calculatorconstructed in accordance with the invention and showing the partsarranged for indicating the price of certain quantities of goods atcertain prices; Fig. 2 is a perspective view illustrating another formof the calculator and showing the parts shifted for indicating the priceof other quantities of goods at other prices; Fig. 3 is a verticalsectional .view of the calculator on the line 3+3 of Fig. 1; Fig. {l isa vertical sectional view taken at right angles to Fig. 3 and on theline 44 of Fig. 1; Fig. 5 is a detail perspective view of another formof the calculator; Fig. 6 is a central vertical sectional view throughthe same.

In the embodiment of the invention I provide a suitable frame or case 1which may be of any suitable shapeand which is preferablyprovidetlwith aglass or other cover plate 2. A The frame or case 1 may be suported inany suitable manner the same being shown in Figs. 1, 3 and 4 of thedrawing as adapted to be laid down fiat on a table.

or counter. Arrangedin the frame or case and secured to the under sideof the glass cover plate 2 or secured at their opposite ends to thesides of the frame as shown in Fig. 3 of the drawings are a series ofstrips 3 said strips being spaced at suitable distances apart andextending transversely across the frame or case as shown. The strips aredivided across their length into a series of spaces in each of which isarranged one or more numerals indicating certain quantities of goodssuch' as pounds, yards, bushels, etc. In the present in stances twonumerals are arranged .one above the other in each of the spaces on thestrips said numerals beingarranged consecutively in numerical orderacross the strips as shown.

Slidably mounted in the frame or case immediately below the strips 3 isva card t which is divided into horizontal lines or spaces correspondingto 'the' spaces between the strips 3. In the spaces next to one or bothedges of the card ais arranged series of numbers which indicate theprices per pound, yard, bushel or other unit of measure of the goods. Inthe spaces between the spaces containing the prices along the outeredges of the card are arranged the total cost or price of the quantitiesof goods indicated in the spaces above on the strips 3, at the price perpound, yard or the like indicated by the number at the opposite ends ofthe line along the edges of the card. Thus to ascertain the price offive pounds of. merchandise at 14 cents a pound it would simply benecessary to glance along the line of numbers in which the 1% cent pricenumber is placed until the space below the five pound space on thestrips 3 immediately above this line is reached when it will beseen'that the lower number of the space immediately below the fivepoundspace of the strip will indicate'the cost of the five pounds at. 14cents per pound which-as will be seen is 70. In this manner the cost ofany number of pounds-at any price per pound indicated on the calculatormay be quickly. and accuratelyascertained.

As shown in the drawings the card 4 is of less length than the fram orcase thus permitting said card to be shifted a suf ficient extent tobring the lines of unit values or prices and total costs back and forthbeneath the strips 3 which are arranged and spaced in the frame for thispurpose. In other words it will be understood that only one-half of theunit price and calculated costs are exposed at one time.

This arrangement provides for a maximum number of calculations in aminimum amount of space.

Arranged in the base or back of the case beneath the card 4: is abacking 5 which is preferably formed of a layer of felt or otheryielding or elastic material which serves to hold the card 4 into closeengagement with the under side of the strips 3. If desired suitablesprings 6 may be arranged in the opposite edges of the frame to engagethe adjacent edges of the card 4 whereby the latter will. be yieldinglyheld in its adjusted position. In order to operate the card 4 the latterhas secured to one or both of its ends a tab 7 of metal or othersuitable material which projects through a slot 8 formed in one or bothends of the frame whereby said tab may be grasped and the card thusshifted to the desired position. In Figs. 5 and 6 of the drawings thecardt is shown as having secured to its under side a centrally disposedreinforcing strip 9 the opposite ends of which project through slots 10in the opposite ends of the frame and form tabs by means of which thecards may be shifted.

In Fig. 2 of the drawings the calculator frame isshown as being arrangedin-a verti- -cal position-and secured at the top or upper end to a deskwhere the same may be readily seen by a person using the desk. Inthe'form of the calculator shown in Fig. 2 the movable price card hasconnected to one side an operating handle 11 which projects through aslot 12 in the edge of the frame as shown. The handle 11 may be securedto the card in any suitable manner and takes the place of the tabs andstrips hereinbefore described for operating or shifting the card.

In Figs.5 and 6 of the drawings the calculator frame is shown as beinghingedly connected at its lower edge to the supporting plate 13 uponwhich the frame may rest in a horizontal or fiat position or may besupported in an inclined position by hinged brace bars 14 whichare-connected to the opposite side edges of the frame and plate asshown. The plate 13 is pivotally mounted on a circular disk orsupporting base 15 whereby said plate and frame may be rev'olved ineither direction to bring the calculator into the desired position.

From the foregoing description taken in connection with the accompanyingdrawings, the. construction and operation of the invention will bereadily understood without requiring a more extended explanation.

Various changes in the form, proportion and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of this invention as defined in theappended claims.

,Having. thus described my invention what I claim is:

1. In a calculator, a frame having a rectangular recess and acommunicating opening extending to one edge of the frame, a rectangular,transparent plate secured in the frame over said recess, a series ofparallel strips secured in spaced relation to the under surface of saidtransparent plat/e, said strips having on their upper exposed surfacesnumbers representing quantities or units of measure, a rectangular cardslidably mounted in the frame beneath said strips, said card containingnumbers representing unit and total prices of goods, a handle extendinglaterally from one edge of said card and working in said opening in theframe, a layer of elastic material in the bottom of the recessed portionof the frame and in con tact with the under surface of said card, andleaf springs arranged in the frame beneath the opposite side edges ofsaid card to 'assist the layer of elastic material to press the cardagainst said strips.

2. In a calculator a supporting plate, a frame or casing hingedlyconnected at one end to said plate, a series of strips secured in saidcasing, said strips having arranged thereon numbers representingquantities or units of I measurement, a card slidably mounted in saidframe, beneath said strips said card containing numbersrepresenting unitand total prices of goods, a reinforcing strip arranged below andsecured to said card, said strip having its ends projecting through thesides of said casing to form handles whereby said card may be shifted tobring the numbers thereon into cooperati've relation and to the numberson said strips,.braces to hold said casing in an inclined position onsaid supporting plate, a base plate arranged below said supporting plateand means to pivotally connect said supporting plate withsaid base platewhereby the calculator may be revolved and brought to any desiredposition.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

' LUTHER B. THOMAS.

Witnesses:

Z. G. PAGE, L. H. PInKLn.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

1 Washington, D. G.

